Method of making steel-girder street-rails



(No Model.)

A. J. MOXHAM. v

METHOD OF MAKING STEEL-GERBER STREET RAILS.

No. 310,457. Patented Jan. 6, 1885.

WZ'ZHEESES. [r2 VEHZUFQ UNITED STATES PATENT OFFICE.

ARTHUR J. MOXHAM, OF JOHNSTOXVN, PENNSYLVANIA.

METHOD OF MAKING STEEL-GIRDER STREET-RAILS.

SPECIFICATIQN forming part of Letters Patent No. 310,457, dated January 6, 1885.

(No model.)

To CLZZ whom it may concern:

Be it known that I, ARTHUR J. MOXHAM, of Johnstown, in the county of Gambria and State of Pennsylvania, have invented a new and useful Method or Process of Making Steel- Girder Street-Rails, which invention is fully set forth and illustrated in the following specification and accompanying drawings.

The object of the invention is to facilitate the manufacture of girder-rails having a wide head and also a wide lower flange or foot.

The invention consists in rolling an ingot or bloom of a shape that will equalize the great irregularity of draft in the finishing or shapingrolls, and thus neutralize the wiredrawing induced by such irregularity, preparatory to subsequently rolling or shaping said ingot or bloom in rolls having passes of requisite number and shape to finish the rail required.

Figure l of the accompanying drawings shows an end view of an ingot or bloom as formed ready to be rolled to finished shape. The full lines a a in said figure show about the minimum amount of change of form from the usual rectangular section of ingot, and the dotted lines b b about the maximum amount of such change. This change thus varies in direct proportion to the relative width of head and web ultimately desired. .Fig. 2 shows one of the finished shapes of rails into which the ingot or bloom shown in Fig. 1 is to be rolled. Fig. 3 shows another finished shape of rail made from a similarly-prepared bloom. Fig. 4 shows a dummy-pass, the dotted lines in which represent the shape and size of the mass to be acted on and show the spreading tendency of the dummy-pass on the upper part of the mass of metal.

The advantages of this method will now be explained.

Experience in the rolling of girder-rails has shown that it is impossible to directly roll out an oblong or square bloom of a size commercially practicable into a rail having an ad visable width both of head or upper flanges and foot or lower flange. This is due to the fact that the wire-drawing brought about in reducing the center or web reduces also 5c the sides not otherwise acted on. It has been the practice, therefore, to remedy this disadvantage (as far as may be by such means) by the use of what is called a dummy groove or pass. Of necessity the dummy-pass only acts by spreading 011 one part of the mass of metal being rolled therein. \Vere this not so, it would be impossible to obtain any great spreading action on the particular parts which it is desirable to spread. lVhether head or foot shall be subjected to the greater action of the dummypass depends upon which it is most desirable shall be the wider. In this re spect practice has varied in different localities or countries. lVherever the width of either the head or the foot exceeds that which would be left by wire-drawing, a dummy-pass is now used. The English practice has been to widen the feet at the expense of the head, thus leaving a narrow head and wide foot. The American practice, however, has been, owing largely to municipal requirements,the reverse of the English, a wide head thus being a necessity; hence the dummy-pass is used to widen the head, and the foot of necessity left to roll out to wire-drawn width only, unaffected, practically, by any specific action of the dummy-pass as such; hence it is practically impossible by this means to obtain a wide foot on the rail adapted to American practice. Furthermore, a dummy-pass is notin all respects an advantageous means of widening any special part of the mass, and its use may be dispensed with to much advantage, for the following reasons: The extent of its action on a piece of a given size depends upon and varies with the distance of the rolls apart. The least irregularityoften inevitable in practice-affects the width resultant from its use; and even with a constant distance of the rolls apart, if one portion of the hot mass of metal acted 011 be cooler than another, the cooler portion will be spread less. For these reasons the dummy-passes are not as regular or satisfactory in their action as are the edging-passes; but the dummypasses can only be dispensed with by partly reducing, previous to the shaping process, that part of the metal which being most worked upon in the finishing or shaping rolls, (the part which forms the web,) induces an excess of wire IOO drawing. It would not be necessary to first make this reduction of the web part if the size of the bloom or ingot to be operated upon by the finishing or shaping rolls proper were unlimited; but the commercial considerations of finishing the blooms at one heating and of quickly handling masses of metal limited as to weight, together with the practical considerations which limit the size of the mill to be used for shaping or rolling, fix a limit to the sizes of the blooms, whose sizes in practice generally vary from seven to nine inches in extreme width. Now, to obviate the de fects and disadvantages above mentioned be ing the object of this invention, it can readily be seen that such may be accomplished by rolling the ingots approximately to the shape desired, shown in the drawings, and with alarger mass of metal of extreme width to form the head, a lighter mass of extreme width to form the flanges or foot, and with a mass of reduced thickness to form the web, an ingot so shaped previous to its being rolled or shaped into the finished form desired will entail so little wire-drawing in the finishing process that the desired widths and shapes of both head and foot can be secured without the use of the dummy-passes. The ingots as originally cast are of such size that the blooming process is in every-day practice a necessity to reduce these ingots to blooms of the required size; hence the partly rolling out the central portion of the ingot or bloom, as hereinafter described, will add nothing to the time or cost of this process. It is a fact that the slower the speed the less the wire drawing, and if the metal has time to yield to vertical stress of the rolls during rolling, it will tend to ilow more in the direction of that stress than to follow the tension induced by the rolls in other portions of the slower speed of the blooming mill, together with a pass or passes acting on the central part only, and not on the edges of the bloom,

it will be possible to retain the desired width at those edges which otherwise could not be so retained in a bloom of feasible dimensions as passed through the finishing-mill, which of necessity is smaller in diameter of pass than the blooming-null, and run at a much greater speed. Furthermore, the slower the speed and the larger the surface acted on, the greater the spread of metal; therefore, in the blooming-mill just described flattening -passes (not dummy-passes) may be used to advantage in conjunction with the edging-passes just described, so that ai'ter the central portion, at a: in the drawings, has been partly rolled out with a minimum of wire-drawing at the edges 7 3 the bloom or ingot (as it may be called by either term now) may be rolled on the flat, and the pass would thus spread all of the mass; but as the edges 9 31 present a larger surface than the central portion, :10, the metal will be spread relatively more at 3 y than at .00, thus assisting in widening the flanges directly and positively.

Having thus fully described my said pro cess as of my invention, 1 claim The above-described method or process of making steel-girder street-rails, consisting in rolling an ingot or bloom thinnest in the center for the web,with a contour approximating that of the finished rail, preparatory to subsequent heating and rolling out of said ingot or bloom into a girder-rail, substantially as set forth.

A. J. MOXHAM.

Vitnesses:

W. R. JONES, RoLLrX E. Bnnns. 

